threat-modeling.md

Threat Model Analysis for iamkun/dayjs

Threat: Denial of Service (DoS) via Malformed Date Strings

• Description: An attacker sends specially crafted, complex, or extremely long date strings to the application. dayjs parsing functions consume excessive CPU and memory resources attempting to parse these strings. This can be achieved by repeatedly sending requests with malicious date strings, overwhelming the server and making the application unresponsive to legitimate users.
• Impact: Application becomes unavailable to users. Server performance degrades significantly or crashes. Financial losses due to downtime and resource consumption. Reputational damage.
• Dayjs Component Affected: Parsing functions (e.g., dayjs(), dayjs.utc(), dayjs.unix(), parsing with specific formats).
• Risk Severity: High
• Mitigation Strategies:
  • Input Validation: Implement strict input validation on all user-provided date strings before passing them to dayjs. Define allowed date formats and reject invalid or overly complex inputs.
  • Parsing Timeouts: Set timeouts for dayjs parsing operations, especially when handling user input. If parsing takes longer than the timeout, abort the operation to prevent resource exhaustion.
  • Rate Limiting: Implement rate limiting on endpoints that process date strings from user input to restrict the number of parsing requests from a single source within a given timeframe.
  • Resource Monitoring: Monitor server resource usage (CPU, memory) to detect and respond to potential DoS attacks early.
  • Regular Updates: Keep dayjs updated to the latest version, as newer versions may contain performance improvements or fixes for parsing-related DoS vulnerabilities.

Threat: Regular Expression Denial of Service (ReDoS) in Parsing

• Description: An attacker crafts specific date strings that exploit vulnerabilities in the regular expressions used by dayjs for parsing. These crafted strings cause the regex engine to backtrack excessively, leading to high CPU usage and a denial of service. The attacker sends requests with these ReDoS-triggering date strings to exhaust server resources.
• Impact: Application becomes unavailable. Server resources are exhausted. Similar impacts to general DoS, including downtime, financial losses, and reputational damage.
• Dayjs Component Affected: Internal regular expressions used within parsing functions.
• Risk Severity: High
• Mitigation Strategies:
  • Code Review and Regex Analysis (for Dayjs Maintainers): Thoroughly review and analyze regular expressions used in dayjs parsing logic for potential ReDoS vulnerabilities. Employ techniques to mitigate backtracking issues in regex design.
  • Input Sanitization and Validation: Sanitize and validate user-provided date strings to limit complexity and format variations, reducing the likelihood of triggering ReDoS vulnerabilities in parsing regex.
  • Use Simpler Parsing Methods: When feasible, utilize simpler, less regex-intensive parsing methods provided by dayjs or alternative approaches, especially for well-defined date formats.
  • Security Testing: Include ReDoS vulnerability testing in security assessments of applications using dayjs.
  • Regular Updates: Keep dayjs updated to benefit from any potential ReDoS vulnerability fixes in newer versions.